Conductive film

Abstract

To provide a conductive film having improved adhesion between a substrate film and a low-reflection layer. [Solution] A conductive film (10) includes, in this order in the thickness direction, a base film (1), a low-reflection layer (2), and a metal layer (3). The low-reflection layer (2) contains Cu and a Cu compound containing Cu2O, and when the total amount of Cu and the Cu compound contained in the low-reflection layer (2) is taken as 100 atomic %, the amount of Cu2O contained in the total amount of Cu and the Cu compound at a position 2.5 nm deep from the surface toward the metal layer (3) is lower than the amount of Cu2O contained in the total amount of Cu and the Cu compound on the surface of the low-reflection layer (2) on the base film (1) side.

Description

[Technical Field]

[0001] The present invention relates to a conductive film. [Background technology]

[0002] In recent years, development has been progressing on conductive films with low-resistivity metal micropatterns as conductive layers for display devices such as touch panels, instead of highly transparent metal oxide layers such as ITO. While the fine metal patterning of conductive films can improve visibility, glare can occur due to the high reflectivity inherent to metal. To address this issue, a technology is known that suppresses reflections from the metal layer by placing a low-reflection layer adjacent to the metal layer.

[0003] As such a conductive film, a laminate has been proposed, which comprises a transparent substrate, a metal layer formed on the substrate, and a low-reflection layer formed in contact with at least one surface of the metal layer. In an example of this laminate, the low-reflection layer is produced by sputtering using a target containing Cu under conditions of a sputtering pressure of 0.16 to 0.44 Pa (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 194587 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in such a conductive film, the adhesion at the interface between the substrate and the low-reflection layer is low, and they may peel off.

[0006] The present invention provides a conductive film having improved adhesion between a substrate film and a low-reflection layer. [Means for solving the problem]

[0007] The present invention [1] includes a conductive film comprising a base film, a low-reflection layer, and a metal layer in this order in the thickness direction, wherein the low-reflection layer contains Cu and a Cu compound containing Cu2O, and the amount of Cu2O contained in the total amount of Cu and the Cu compound at a position 2.5 nm deep from the surface toward the metal layer is lower than the amount of Cu2O contained in the total amount of Cu and the Cu compound at the surface of the low-reflection layer facing the base film.

[0008] The present invention [2] includes the conductive film according to the above [1], wherein the low-reflection layer contains an In compound containing InOx, and the amount of InOx in the In compound on the surface is 80 atomic % or more.

[0009] The present invention [3] includes the conductive film according to the above [1] or [2], wherein the low-reflection layer has a thickness of 3 nm or more. [Effects of the Invention]

[0010] The conductive film of the present invention comprises a substrate film, a low-reflection layer, and a metal layer, in this order in the thickness direction. The low-reflection layer contains Cu and a Cu compound containing CuO, and the amount of CuO contained in the total amount of Cu and the Cu compound at a depth of 2.5 nm from the surface toward the metal layer is lower than the amount of CuO contained in the total amount of Cu and the Cu compound at the surface of the low-reflection layer facing the substrate film. Therefore, the adhesiveness between the substrate film and the low-reflection layer in the conductive film can be improved. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view of one embodiment of the conductive film of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view of a modified example of the conductive film of the present invention. [Figure 3]FIG. 3 is a schematic diagram showing the procedure of the peel measurement method for the conductive film of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing the procedure of the peel measurement method for the conductive film of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1. First embodiment <Conductive film> A conductive film 10 according to one embodiment of the present invention is shown in Fig. 1. The conductive film 10 includes a base film 1, a low-reflection layer 2, and a metal layer 3, in this order. The base film 1, the low-reflection layer 2, and the metal layer 3 are arranged in this order in the conductive film 10 from one side to the other side in the thickness direction.

[0013] The conductive film 10 has, for example, a film shape (including a sheet shape) with a predetermined thickness. The conductive film 10 extends in a plane direction perpendicular to the thickness direction. One surface (lower surface) and the other surface (upper surface) in the thickness direction of the conductive film 10 are, for example, flat. The conductive film 10 is flexible.

[0014] From the viewpoints of strength and ease of handling, the thickness of the conductive film 10 is, for example, 5 μm or more, preferably 20 μm or more, more preferably 50 μm or more, and even more preferably 80 μm or more, and for example, 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less.

[0015] The luminous reflectance (Y value) of the conductive film 10 measured from the other side of the base film 1 is, from the viewpoint of ensuring the light absorption of the low-reflection layer 2, for example, 20% or less, preferably 15% or less, more preferably 10% or less, and even more preferably 8% or less, and is, for example, 1% or more. The luminous reflectance (Y value) is measured by scanning in a measurement range of wavelengths from 380 to 780 nm using a spectrophotometer.

[0016] [Base film] The base film 1 is the lowermost layer of the conductive film 10 and is a support film that ensures the strength of the conductive film 10. The base film 1 contacts the other surface of the low-reflection layer 2 in the thickness direction.

[0017] The base film 1 has a film shape (including a sheet shape) and is, for example, a flexible, transparent resin film.

[0018] From the viewpoint of the strength and handleability of the conductive film 10, the thickness of the base film 1 is, for example, 5 μm or more, preferably 20 μm or more, more preferably 50 μm or more, and even more preferably 80 μm or more, and for example, 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less.

[0019] The thickness of the substrate film 1 can be measured using, for example, a film thickness meter.

[0020] The visible light transmittance (JISK-7105) of the base film 1 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more, and for example, 100% or less.

[0021] 1, the base film 1 includes a transparent film 1a, a first cured resin layer 1b, and a second cured resin layer 1c. The first cured resin layer 1b is disposed on one surface of the transparent film 1a in the thickness direction. The second cured resin layer 1c is disposed on the other surface of the transparent film 1a in the thickness direction.

[0022] (Transparent film) The transparent film 1a has a film shape (including a sheet shape) and is, for example, a flexible, transparent resin film.

[0023] Examples of materials for the transparent film 1a include resins. Examples of resins include cellulose resins, polyester resins, (meth)acrylic resins (acrylic resins and / or methacrylic resins), olefin resins, polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, polystyrene resins, norbornene resins, and polyvinyl alcohol resins. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of cellulose resins include triacetyl cellulose (TAC). From the viewpoints of transparency, heat resistance, mechanical strength, and the like, the transparent film 1a is preferably a polyester film. More preferably, a cycloolefin resin film or a polyethylene terephthalate film is used, and even more preferably, a cycloolefin resin film is used. The materials for the transparent film 1a can be used alone or in combination of two or more types.

[0024] From the viewpoint of the strength and handleability of the conductive film 10, the thickness of the transparent film 1a is, for example, 5 μm or more, preferably 20 μm or more, more preferably 50 μm or more, and even more preferably 80 μm or more, and for example, 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less.

[0025] The thickness of the transparent film 1a can be measured using, for example, a film thickness meter.

[0026] (1st cured resin layer) The first cured resin layer 1b has a film shape and is disposed on one surface of the transparent film 1a in the thickness direction. The first cured resin layer 1b is disposed between the transparent film 1a and the low-reflection layer 2. The first cured resin layer 1b contacts the transparent film 1a.

[0027] Examples of the first cured resin layer 1b include a hard coat layer, an optical adjustment layer, and an anti-blocking layer. The hard coat layer is, for example, a layer that makes the exposed surface of the transparent film 1a less susceptible to scratches. The optical adjustment layer is, for example, a layer that adjusts the optical properties (e.g., refractive index) of the conductive film 10. The anti-blocking layer is, for example, a layer that imparts anti-blocking properties to the surfaces of multiple conductive films 10 that come into contact with each other when the conductive films 10 are stacked in the thickness direction.

[0028] The first cured resin layer 1b is a cured product of a curable resin composition. Specifically, the first cured resin layer 1b can be formed by applying a curable resin composition to one surface in the thickness direction of the transparent film 1a, drying the composition as necessary, and then curing the composition.

[0029] The curable resin composition is a composition containing a curable resin, and examples thereof include a composition containing an ultraviolet-curable resin and a composition containing a thermosetting resin. From the viewpoint of production efficiency, the curable resin composition is preferably a composition containing an ultraviolet-curable resin. In other words, the first cured resin layer 1b is preferably a cured product layer of a composition containing an ultraviolet-curable resin.

[0030] Examples of ultraviolet curable resins include (meth)acrylate resins. Examples of (meth)acrylate resins include acrylic urethane resins and acrylic resins (excluding acrylic urethane resins). Preferably, acrylic urethane resins are used. Also included are copolymers of acrylic urethane resins and polyfunctional acrylates. The ultraviolet curable resins can be used alone or in combination of two or more. The (meth)acrylate resin is a methacrylate resin and / or an acrylate resin.

[0031] That is, the curable resin composition preferably contains a (meth)acrylate resin, more preferably contains an acrylic urethane resin, and more preferably contains a copolymer of an acrylic urethane resin and a polyfunctional acrylate.

[0032] The curable resin composition may contain other ultraviolet curable resins.

[0033] Examples of other ultraviolet curable resins include polyester resins, urethane resins (excluding acrylic urethane resins), amide resins, epoxy resins, and melamine resins. The other ultraviolet curable resins can be used alone or in combination of two or more.

[0034] The curable resin composition may contain particles. The curable resin composition preferably contains particles.

[0035] Examples of particles include organic particles and inorganic particles.

[0036] Examples of materials for the organic particles include polymethyl methacrylate, polystyrene, acrylic-styrene copolymer, and polycarbonate.

[0037] Examples of inorganic particles include inorganic oxide particles. Materials for inorganic oxide particles include metal oxides and semi-metal oxides, specifically silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. The inorganic oxide particle material may also be a metal composite oxide in which the above-mentioned metal oxides are combined. Furthermore, functional groups such as acrylic groups and epoxy groups may be introduced onto the surface of the inorganic oxide particles in order to enhance adhesion and affinity with resins.

[0038] The average primary particle size of the particles is not particularly limited and is, for example, 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and for example, 500 nm or less, preferably 300 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less.

[0039] The average particle size of the particles can be measured by the specific surface area measurement (BET) method.

[0040] The particle content in the curable resin composition (solid content) is, for example, 0.1 parts by mass or more, preferably 1 part by mass or more, more preferably 5 parts by mass or more, and for example, 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, relative to 100 parts by mass of the curable resin.

[0041] The thickness of the first cured resin layer 1b is, from the viewpoints of scratch resistance and suppressing visibility of the wiring pattern, for example, 0.1 μm or more, or preferably 0.5 μm or more, and for example, 10 μm or less, or preferably 5 μm or less.

[0042] The thickness of the first cured resin layer 1b can be measured, for example, by a spectroscopic ellipsometer.

[0043] (Second cured resin layer) The second cured resin layer 1c is disposed on the outermost surface on the other thickness direction side of the conductive film 10. The second cured resin layer 1c is disposed on the other thickness direction surface of the transparent film 1a. The second cured resin layer 1c is in contact with the transparent film 1a.

[0044] Examples of the second cured resin layer 1c include a hard coat layer, an optical adjustment layer, and an anti-blocking layer. The hard coat layer is, for example, a layer that makes the exposed surface of the transparent film 1a less susceptible to scratches. The optical adjustment layer is, for example, a layer that adjusts the optical properties (e.g., refractive index) of the conductive film 10. The anti-blocking layer is, for example, a layer that imparts anti-blocking properties to the surfaces of multiple conductive films 10 that come into contact with each other when the conductive films 10 are stacked in the thickness direction.

[0045] The second cured resin layer 1c is a cured product of a curable resin composition. The curable resin composition used for the second cured resin layer 1c is the same as the curable resin composition used for the first cured resin layer 1b, and the second cured resin layer 1c is formed by the same method as the first cured resin layer 1b.

[0046] The thickness of the second cured resin layer 1c is, from the viewpoints of scratch resistance and suppressing visibility of the wiring pattern, for example, 0.1 μm or more, or preferably 0.5 μm or more, and for example, 10 μm or less, or preferably 5 μm or less.

[0047] The thickness of the second cured resin layer 1c can be measured, for example, by a spectroscopic ellipsometer.

[0048] [Low reflective layer] The low-reflection layer 2 is disposed on one surface in the thickness direction of the base film 1. The low-reflection layer 2 is in contact with one surface of the base film 1 in the thickness direction.

[0049] The low-reflection layer 2 is a layer that can lower the reflectance measured from the substrate film 1 side when the low-reflection layer 2 is placed between the substrate film 1 and the metal layer 3, compared to when the metal layer 3 is placed directly on the substrate film 1. In other words, the low-reflection layer 2 is a layer with high light absorption, such as a blackened layer. In the conductive film 10, the low-reflection layer 2 reduces the visibility of the metal layer 3 from the substrate film 1 side.

[0050] The low-reflection layer 2 contains a metal compound and a metal (elementary metal). Examples of the metal compound include metal oxides, metal hydroxides, metal nitrides, and metal carbides. Note that the metal compound is a compound of a metal and a non-metal.

[0051] The low reflective layer 2 contains CuO (copper oxide (I)) as a metal compound. The low reflective layer 2 preferably contains, in addition to CuO, one or more of CuO (copper oxide (II)) and CuOH (copper hydroxide). The low reflective layer 2 may further contain other Cu (copper) compounds.

[0052] Furthermore, from the viewpoint of realizing high light absorption, the low-reflective layer 2 preferably contains InOx (indium oxide) as a metal compound. More preferably, the low-reflective layer 2 contains InOx and In(OH)x (indium hydroxide). The low-reflective layer 2 may further contain other In (indium) compounds.

[0053] The low reflective layer 2 may contain metal compounds other than the above-mentioned metal compounds.

[0054] Examples of other metal compounds include metal compounds other than Cu (copper) and In (indium) (e.g., metal oxides, metal hydroxides, metal nitrides, and metal carbides, preferably metal oxides). Examples of metals other than Cu (copper) and In (indium) include Mo (molybdenum) and Fe (iron).

[0055] The low reflective layer 2 contains Cu (copper) as a metal (elementary metal). The low reflective layer 2 preferably contains In (indium) in addition to Cu.

[0056] The low reflective layer 2 may contain other elemental metals in addition to the above-mentioned elemental metals.

[0057] Other elemental metals include, for example, Mo (molybdenum) and Fe (iron).

[0058] The proportion of the metal compound in the low reflective layer 2 is preferably 5 atomic % or more, more preferably 15 atomic % or more, and is preferably 95 atomic % or less, more preferably 85 atomic % or less, when the total amount of the metal compound and the elemental metal is taken as 100 atomic %, from the viewpoint of realizing high light absorption in the low reflective layer 2. That is, the proportion of the metal compound in the low reflective layer 2 is preferably 5 to 95 atomic %, more preferably 15 to 85 atomic %.

[0059] The proportion of the elemental metal in the low reflective layer 2 is preferably 5 atomic % or more, more preferably 15 atomic % or more, and is preferably 95 atomic % or less, more preferably 85 atomic % or less, when the total amount of the metal compound and the elemental metal is taken as 100 atomic %, from the viewpoint of realizing high light absorption in the low reflective layer 2. That is, the proportion of the elemental metal in the low reflective layer 2 is preferably 5 to 95 atomic %, more preferably 15 to 85 atomic %.

[0060] The proportion of copper in the low-reflection layer 2 is preferably 5 atomic % or more, more preferably 10 atomic % or more, and is preferably 50 atomic % or less, more preferably 40 atomic % or less, from the viewpoint of realizing high light absorption in the low-reflection layer 2, when the total amount of the metal compound and the elemental metal is taken as 100 atomic %.

[0061] When the low-reflective layer 2 contains indium oxide, the proportion of In in the low-reflective layer 2 is preferably 40 atomic % or more, more preferably 50 atomic % or more, and is preferably 90 atomic % or less, more preferably 85 atomic % or less, from the viewpoint of realizing high light absorption in the low-reflective layer 2, when the total amount of the metal compound and the elemental metal is taken as 100 atomic %.

[0062] The low reflective layer 2 may contain an organic material, but preferably does not contain an organic material from the viewpoint of light resistance.

[0063] When an organic material is included, the low-reflection layer 2 includes, for example, a thermoplastic resin and a colorant. The thermoplastic resin is not particularly limited. The colorant is not particularly limited as long as it is a black colorant, and examples thereof include carbon black.

[0064] Furthermore, in the low-reflection layer 2, the amount (atomic %) of metal compounds contained in the total amount (100 atomic %) of metal compounds and elemental metals is lower at a position (atomic %) at a predetermined depth from the other surface in the thickness direction than at the other surface in the thickness direction. That is, the amount (atomic %) of Cu2O contained in the total amount of Cu and Cu compounds at a position 2.5 nm deep from the surface toward the metal layer 3 is lower than the amount (atomic %) of Cu2O contained in the total amount (100 atomic %) of Cu and Cu compounds on the surface of the low-reflection layer 2 on the substrate film 1 side.

[0065] That is, the amount of Cu2O contained in the total amount of Cu and Cu compounds on the surface of the low-reflective layer 2 facing the base film 1 is large. Cu2O (copper oxide (I)) has a smaller number of oxygen bonds to copper than CuO (copper oxide (II)), which means that there is less oxygen bonded to Cu on the surface of the low-reflective layer 2 facing the base film 1. Furthermore, Cu2O (copper oxide (I)) bonds more strongly to the base film 1 than CuO (copper oxide (II)), and as a result, the adhesion between the base film 1 and the low-reflective layer 2 can be improved.

[0066] Furthermore, the amount of Cu2O (atomic %) contained in the total amount (100 atomic %) of Cu and Cu compounds on the surface of the low-reflective layer 2 facing the substrate film 1 is, for example, 9 atomic % or more, preferably 10 atomic % or more, more preferably 11 atomic % or more, and for example, 20 atomic % or less, preferably 15 atomic % or less. By setting the amount of Cu2O on the surface facing the substrate film 1 within the above range, the adhesion between the substrate film 1 and the low-reflective layer 2 can be further improved.

[0067] Furthermore, the amount of CuO (atomic %) contained in the total amount (100 atomic %) of Cu and Cu compounds on the surface of the low-reflective layer 2 facing the substrate film 1 is, for example, 2.5 atomic % or less, preferably 2.0 atomic % or less, more preferably 1.5 atomic % or less, even more preferably 1.0 atomic % or less, and for example, 0 atomic % or more. By setting the amount of CuO on the surface facing the substrate film 1 within the above range, the adhesion between the substrate film 1 and the low-reflective layer 2 can be further improved.

[0068] Furthermore, the amount (atomic %) of CuO contained in the total amount (100 atomic %) of Cu and Cu compounds at a depth of 2.5 nm from the surface of the low-reflective layer 2 on the substrate film 1 side toward the metal layer 3 is, for example, 1 atomic % or more, preferably 2 atomic % or more, more preferably 3 atomic % or more, and for example, 9 atomic % or less, preferably 7 atomic % or less, more preferably 5 atomic % or less. By setting the amount of CuO at a depth of 2.5 nm from the surface of the low-reflective layer 2 on the substrate film 1 side toward the metal layer 3 within the above range, the adhesion between the substrate film 1 and the low-reflective layer 2 can be further improved.

[0069] Furthermore, the amount (atomic %) of InOx in the In compounds (100 atomic %) contained in the low-reflective layer 2 on the surface facing the substrate film 1 is, for example, 80 atomic % or more, preferably 82 atomic % or more, more preferably 84 atomic % or more, and for example, 95 atomic % or less, preferably 90 atomic % or less. By setting the amount of InOx on the surface facing the substrate film 1 within the above range, the adhesion between the substrate film 1 and the low-reflective layer 2 can be further improved.

[0070] The thickness of the low reflective layer 2 is, for example, 3 nm or more, preferably 4 nm or more, more preferably 6 nm or more, even more preferably 8 nm or more, particularly preferably 10 nm or more, and most preferably 12 nm or more, and for example, 100 nm or less, preferably 60 nm or less, more preferably 40 nm or less, particularly preferably 25 nm or less, and most preferably 20 nm or less.

[0071] The thickness of the low reflective layer 2 can be measured, for example, by a spectroscopic ellipsometer.

[0072] [Metal layer] The metal layer 3 is disposed on one side of the low-reflection layer 2 in the thickness direction of the conductive film 10. The metal layer 3 contacts one surface in the thickness direction of the low-reflection layer 2. The metal layer 3 is, for example, a conductor layer or a wiring layer.

[0073] Examples of metals that can form the metal layer 3 include gold, silver, copper, nickel, aluminum, magnesium, tungsten, cobalt, zinc, iron, and alloys thereof. Gold, silver, and copper are preferred, and copper is more preferred from the viewpoints of cost and processability.

[0074] The thickness of the metal layer 3 is, for example, 10 nm or more, preferably 40 nm or more, more preferably 80 nm or more, even more preferably 150 nm or more, and for example, 2000 nm or less, preferably 1000 nm or less, more preferably 500 nm or less, even more preferably 300 nm or less.

[0075] The thickness of the metal layer 3 can be measured, for example, by a spectroscopic ellipsometer.

[0076] <Method of manufacturing conductive film> Next, a description will be given of a method for manufacturing the conductive film 10. The conductive film 10 is manufactured, for example, by a roll-to-roll method as follows.

[0077] The method for manufacturing the conductive film 10 includes, for example, a preparation step of preparing the base film 1, and a film formation step of laminating the low-reflection layer 2 and the metal layer 3 in this order on one surface of the base film 1 in the thickness direction.

[0078] (Preparation process) In the preparation step, first, a transparent film 1a is prepared, and then a first cured resin layer 1b is laminated on one thickness-wise surface of the transparent film 1a, and a second cured resin layer 1c is laminated on the other thickness-wise surface of the transparent film 1a.

[0079] To laminate the first cured resin layer 1b and the second cured resin layer 1c, for example, a dilution is prepared by diluting the above-mentioned curable resin composition with a solvent. The dilution is applied to one thickness-wise surface of the transparent film 1a, the dilution is dried, and the curable resin composition is cured with ultraviolet light to form the first cured resin layer 1b. Next, the dilution is applied to the other thickness-wise surface of the transparent film 1a, the dilution is dried, and the curable resin composition is cured with ultraviolet light to form the second cured resin layer 1c.

[0080] This provides a substrate film 1 comprising a transparent film 1a, a first cured resin layer 1b laminated on one thickness-wise surface of the transparent film 1a, and a second cured resin layer 1c laminated on the other thickness-wise surface of the transparent film 1a.

[0081] (Film forming process) The low-reflection layer 2 and the metal layer 3 are formed by, for example, a dry coating method. Examples of dry coating methods include sputtering and vapor deposition. Sputtering is preferred. Examples of sputtering methods include dipole sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Magnetron sputtering is preferred.

[0082] Examples of the power source for applying a voltage to the target in the film formation step include a DC power source, an AC power source, an MF power source, and an RF power source, and preferably a DC power source.

[0083] Specifically, in the sputtering method, a sputtering gas (inert gas) is introduced into each deposition chamber of the sputter deposition apparatus under vacuum conditions, while a negative voltage is applied to a target placed on a cathode in each deposition chamber. This generates a glow discharge, ionizing the gas atoms, causing these gas ions to collide with the target surface at high speed, ejecting target material from the target surface, which is then deposited in sequence on the substrate film 1.

[0084] In the film formation process of this embodiment, a low-reflection layer 2 and a metal layer 3 are laminated in this order on one surface in the thickness direction of the substrate film 1. Specifically, in the first sputtering film formation, the low-reflection layer 2 is formed on one surface in the thickness direction of the substrate film 1 (low-reflection layer formation process), and then, in the second sputtering film formation, the metal layer 3 is formed on one surface in the thickness direction of the low-reflection layer 2 (metal layer formation process). That is, the film formation process includes a low-reflection layer formation process and a metal layer formation process.

[0085] The sputtering gas used in the first sputtering film formation (low reflective layer forming step) may be an inert gas, such as argon, krypton, xenon, or a mixture thereof, preferably argon.

[0086] A reactive gas (e.g., oxygen) can also be used as the sputtering gas. When a reactive gas is used, the amount of the reactive gas is, in terms of flow rate ratio, for example, 20% by volume (vol%) or less, preferably 15% by volume or less, more preferably 10% by volume or less, and even more preferably 5% by volume or less.

[0087] As the sputtering gas, an inert gas is preferably used, and more preferably, only an inert gas is used. By using only an inert gas as the sputtering gas, the color of the low reflective layer 2 can be improved.

[0088] The air pressure in the film formation chamber during the first sputtering film formation (low-reflection layer formation process) (the air pressure in the film formation chamber when the sputtering gas, or the sputtering gas and the reactive gas, are introduced) is, for example, 0.45 Pa or more, preferably 0.6 Pa or more, more preferably 0.7 Pa or more, even more preferably 0.8 Pa or more, and for example, 2.0 Pa or less, preferably 1.6 Pa or less, more preferably 1.2 Pa or less, even more preferably 1.1 Pa or less.

[0089] By setting the pressure in the deposition chamber for the first sputtering deposition within the above range, the amount of Cu2O in the total amount of Cu and Cu compounds at a position 2.5 nm deep from the surface toward the metal layer 3 can be made lower than the amount of Cu2O in the total amount of Cu and Cu compounds on the surface of the low-reflective layer 2 facing the base film 1. As a result, the adhesion between the base film 1 and the low-reflective layer 2 in the conductive film 10 can be improved.

[0090] This is because, for example, under conditions of a relatively low atmospheric pressure (e.g., 0.3 to 0.4 Pa) in the film formation chamber, atoms colliding with the substrate film 1 by sputtering have high energy. Therefore, when the low-reflection layer 2 is formed on the substrate film 1, atoms with high energy collide, and these collisions cause gases such as oxygen to be generated from the substrate film 1. The generated gas then makes it easier for CuO (copper oxide (II)) to be formed on the surface of the low-reflection layer 2 facing the substrate film 1 than CuO (copper oxide (I)). On the other hand, if the atmospheric pressure in the film formation chamber is set relatively high as described above, the energy of atoms colliding with the substrate film 1 by sputtering is lowered, and therefore the generation of gases such as oxygen is relatively reduced. Therefore, when the low-reflection layer 2 is formed on the substrate film 1, the formation of CuO (copper oxide (II)) is suppressed, and more CuO (copper oxide (I)) is formed on the surface of the low-reflection layer 2 facing the substrate film 1.

[0091] The film formation temperature (temperature of the substrate film 1 during film formation) in the first sputtering film formation (low-reflection layer formation process) is, for example, 150°C or less, preferably 100°C or less, more preferably 50°C or less, and for example, -20°C or more, preferably 0°C or more, more preferably 30°C or more.

[0092] In the first sputtering deposition (low reflective layer forming step), the target material placed on the cathode in the deposition chamber can be the above-mentioned material for the low reflective layer 2. Specifically, the target material for forming the low reflective layer 2 can be, for example, a metal or a metal oxide, and preferably, Cu (copper) and indium oxide.

[0093] The sputtering gas used in the second sputter deposition (metal layer forming step) may be an inert gas, such as argon, krypton, xenon, or a mixture thereof, preferably argon.

[0094] A reactive gas (e.g., oxygen) can also be used as the sputtering gas. When a reactive gas is used in combination, the amount of the reactive gas used is, for example, 20% by volume (vol%) or less, preferably 15% by volume or less, more preferably 10% by volume or less, and even more preferably 5% by volume or less, in terms of flow rate ratio.

[0095] The air pressure in the film formation chamber during the second sputtering film formation (metal layer formation process) is, for example, 0.02 Pa or more, preferably 0.1 Pa or more, more preferably 0.2 Pa or more, and for example, 1.0 Pa or less, preferably 0.6 Pa or less, more preferably 0.5 Pa or less.

[0096] The film formation temperature (temperature of the substrate film 1 on which the low-reflection layer 2 is formed) in the second sputtering film formation (metal layer formation process) is, for example, 150°C or less, preferably 100°C or less, more preferably 50°C or less, and for example, -20°C or more, preferably 0°C or more, more preferably 30°C or more.

[0097] The material of the target placed on the cathode in the film formation chamber in the second sputtering film formation (metal layer formation step) can be the above-mentioned material of the metal layer 3. Specifically, the target material for forming the metal layer 3 can be a metal, such as Cu (copper).

[0098] In this manner, a conductive film 10 is obtained which comprises the substrate film 1, the low-reflection layer 2, and the metal layer 3 in this order.

[0099] <Action and effect> The conductive film 10 of the present invention comprises a base film 1, a low-reflection layer 2, and a metal layer 3, in this order in the thickness direction. The low-reflection layer 2 contains Cu and a Cu compound containing CuO, and the amount of CuO contained in the total amount of Cu and the Cu compound at a position 2.5 nm deep from the surface toward the metal layer 3 is lower than the amount of CuO contained in the total amount of Cu and the Cu compound at the surface of the low-reflection layer facing the base film 1. Therefore, the adhesion between the base film 1 and the low-reflection layer 2 in the conductive film 10 can be improved.

[0100] 2. Variations A conductive film 10a according to a modified example of the present invention is shown in FIG. Similar to the first embodiment, the conductive film 10a includes a base film 1, a low-reflection layer 2, and a metal layer 3 in this order. However, in the conductive film 10a, the base film 1 does not include a first cured resin layer 1b and a second cured resin layer 1c, and is composed only of a transparent film 1a. In this case, the conductive film 10a is composed of only three layers: the base film 1, the low-reflection layer 2, and the metal layer 3. [Example]

[0101] The present invention will be described in more detail below with reference to examples and comparative examples. It should be noted that the present invention is not limited to these examples and comparative examples. The specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be substituted with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of the Invention" above.

[0102] <Conductive film manufacturing> Example 1 First, a cycloolefin resin (COP) film (product name "ZEONOR ZF16", thickness 100 μm, manufactured by ZEON Corporation) was prepared as a transparent film. A curable resin composition C1 was applied to one surface of the COP film in the thickness direction to form a coating. The curable resin composition C1 contained 100 parts by mass (resin content) of a UV-curable urethane acrylate resin (product name "AIKATRON Z844L", manufactured by AICA Corporation), 10 parts by mass of silica particles (product name "CSZ9281", average primary particle diameter 30 nm, manufactured by CIK Nanotech), and methyl isobutyl ketone as a solvent. Next, the coating on the COP film was dried and then cured by UV irradiation to form a first cured resin layer with a thickness of 1 μm.

[0103] Next, a curable resin composition C2 was applied to the other thickness-wise surface of the COP film on which the first cured resin layer had been formed to form a coating. The curable resin composition C2 contained 100 parts by mass (solids) of a UV-curable urethane acrylate resin (product name "Aikatron Z844L" manufactured by AICA Corporation), 10 parts by mass of silica particles (product name "CSZ9281" with an average primary particle diameter of 30 nm manufactured by CIK Nanotech Co., Ltd.), and methyl isobutyl ketone as a solvent. The coating on the COP film was then dried and cured by UV irradiation to form a second cured resin layer with a thickness of 1 μm.

[0104] This resulted in the preparation of a substrate film comprising a COP film, a first cured resin layer laminated on one surface of the COP film in the thickness direction, and a second cured resin layer laminated on the other surface of the COP film in the thickness direction (preparation process).

[0105] Next, a low-reflection layer and a metal layer were deposited in this order on one surface of the first cured resin layer in the thickness direction by sputtering. This deposition process was performed using a roll-to-roll sputter deposition apparatus (DC magnetron sputter deposition apparatus). The apparatus was equipped with a feed chamber, a first deposition chamber, a second deposition chamber, and a take-up chamber.

[0106] In the film formation process, the substrate film unwound from the unwinding chamber was subjected to a first sputtering deposition (low-reflection layer formation process) to form a low-reflection layer in the first deposition chamber, and a second sputtering deposition (metal layer formation process) to form a metal layer in the second deposition chamber, followed by winding up the conductive film in the winding chamber. In the first sputtering deposition, a low-reflection layer with a thickness of 15 nm was formed on one surface of the substrate film in the thickness direction. In the subsequent second sputtering deposition, a copper layer with a thickness of 200 nm was formed on one surface of the low-reflection layer in the thickness direction. The conditions for each sputtering deposition were as follows:

[0107] In the first sputtering deposition (low-reflection layer formation step), a low-reflection layer (In2O3+Cu layer) was deposited on one surface of the substrate film in the thickness direction. Specifically, after evacuating the sputtering deposition apparatus, argon was introduced as a sputtering gas into the first deposition chamber, and the pressure inside the first deposition chamber was set to 0.9 to 1.0 Pa. The target used was a copper indium oxide target (product name "In2O3+Cu", copper indium oxide, In2O3 ratio 81.2 (±1) mass%, Cu ratio 18.8 mass%, manufactured by Mitsui Mining & Smelting Co., Ltd.). A DC power supply was used as the power source for applying voltage to the target. The deposition temperature (temperature of the substrate film) was set to 40°C.

[0108] In the second sputtering deposition (metal layer forming step), a copper layer was deposited on one surface in the thickness direction of the low reflective layer. Specifically, after evacuating the sputtering deposition apparatus, argon was introduced as a sputtering gas into the second deposition chamber, and the pressure in the second deposition chamber was set to 0.3 to 0.4 Pa. A Cu target was used as the target. A DC power supply was used as the power source for applying voltage to the target. The deposition temperature (the temperature of the substrate film on which the low reflective layer was formed) was set to 40°C.

[0109] As described above, the conductive film of Example 1 was produced, which had a base film (with a cured resin layer on both sides, thickness 102 μm), a low-reflection layer (In2O3+Cu layer, thickness 15 nm), and a metal layer (copper layer, thickness 200 nm) arranged in this order toward one side in the thickness direction.

[0110] Example 2 A conductive film was produced in the same manner as in Example 1, except that in the first sputtering deposition (low reflective layer forming step), oxygen was introduced as the sputtering gas in addition to argon at a flow rate of 0.5% by volume.

[0111] (Comparative Example 1) In the first sputtering deposition (low-reflection layer formation process), a conductive film was produced in the same manner as in Example 1, except that when argon was introduced into the first deposition chamber as a sputtering gas, the air pressure inside the first deposition chamber was set to 0.3 to 0.4 Pa.

[0112] [Table 1]

[0113] <Evaluation> [Composition analysis] The conductive film of each example was cut into a 1 cm size to serve as a sample, which was then fixed on a sample stage and analyzed for composition using an X-ray photoelectron spectrometer (product name "Quantera SXM", manufactured by ULVAC-PHI, Inc.) under the conditions shown in Table 2.

[0114] A wide-scan measurement was performed on the surface of the low-reflection layer on the substrate film side (0 nm depth), and qualitative analysis was performed to calculate the element ratios (atomic %) of the surface. A depth profile was then measured using Ar ion etching, and the element ratios were calculated at a depth of 2.5 nm from the surface of the low-reflection layer toward the metal layer (2.5 nm depth). From the results, the bonding states of Cu and In elements were analyzed, and the bonding state ratios per element were calculated. The compounds corresponding to each state were also determined, and their ratios are shown in the table. The results for Cu element are shown in Table 3, and the results for In element are shown in Table 4.

[0115] [Table 2]

[0116] [Table 3]

[0117] [Table 4]

[0118] [Peel characteristics] The initial peel strength of each conductive film was evaluated by the following procedure, as shown in Figures 3 and 4. Note that the first cured resin layer and the second cured resin layer are omitted in Figures 3 and 4.

[0119] The conductive film of each example was cut into a size of 300 × 200 mm (Fig. 3A). One surface in the thickness direction of the copper layer was electroplated with copper under the following conditions so that the copper layer had a total thickness of 20 μm (Fig. 3B). Equipment: Batch plating tester (manufactured by Yamamoto Plating Tester Co., Ltd.) Conditions: Constant current 2ASD(12A)

[0120] A conductive film with a copper layer thickness of 20 μm was cut into a size of 10 mm × 100 mm, and the conductive film was then attached with a hand roller to a metal supporting substrate 5 (SUS plate) to which adhesive tape 6 (product name: Scotch PPS-15, manufactured by 3M) had been attached (FIG. 3C).

[0121] Next, two 100 mm incisions C were made in the widthwise center of the conductive film, spaced 5 mm apart along the longitudinal direction, using a cutter (Fig. 3Da, Fig. 3Db). Then, in a section 0 to 30 mm from one side in the longitudinal direction (Fig. 4E), the conductive film between incisions C was peeled between the base film 1 and the low-reflection layer 2. In this way, test samples of each example were prepared, each having a "trigger S" that was the peeled portion in the section 0 to 30 mm from one side in the longitudinal direction (Fig. 4F).

[0122] Each test sample was then placed in an autograph (product name "AG-IS," manufactured by Shimazu Corporation), and the load cell was connected to one side of the "Kikake S" in the thickness direction via tape. The sample was then peeled at a peel angle of 180° and a peel speed of 50 mm / min from one side in the longitudinal direction, from 30 to 80 mm (Figure 4G). The force applied to the load cell during peeling was output as data. The average force applied to the load cell in the 40 to 70 mm section from one side in the longitudinal direction was taken as the peel force. The peel force evaluation results are shown in Table 5.

[0123] [Table 5] [Explanation of symbols]

[0124] 1. Base film 2 Low reflective layer 3 metal layer 10, 10a Conductive film

Claims

1. a substrate film, a low-reflection layer, and a metal layer in this order in a thickness direction; The low reflective layer is made of Cu and Cu ２ and a Cu compound containing O, The Cu contained in the total amount of the Cu and the Cu compound on the surface of the low reflection layer on the side of the substrate film ２ The amount of Cu contained in the total amount of the Cu and the Cu compound at a position 2.5 nm deep from the surface toward the metal layer is ２ Conductive film with low O content.

2. the low reflective layer contains an In compound including InOx, The conductive film according to claim 1 , wherein the amount of InO x in the In compound on the surface is 80 atomic % or more.

3. The conductive film according to claim 1 , wherein the low-reflection layer has a thickness of 3 nm or more.

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